In this paper, we demonstrate the characteris- tics of strong internal solitons at the southern edge of Dong- sha Islands in the northern South China Sea (SCS) during May―June 1998, using in situ time series data from the con- ductivity temperature depth (CTD), acoustic Doppler current profiler (ADCP) and thermistor chain. Our measurements indicated that the strongest internal solitons were larger than 90 m in wave amplitude, and propagated approximately westward in traveling direction, with the maximum current speed of about 2 m/s and the period of 10―20 min. The strongest internal solitons occurred noticeably during May 14―16, 1998, which is consistent with the occurrence period of the diurnal-dominated spring internal tides.
